John O’Sullivan, the Worth Township Democratic committeeman, served a short stint as a state lawmaker before Preckwinkle in May named him to an $85,000-a-year post as a regional superintendent at the forest preserve.

Preckwinkle, who ran as a reformer, faced criticism for hiring O'Sullivan, who according to an inspector general's report had been fired from a previous county job for falsifying his time cards. Preckwinkle said then that her concerns were alleviated because he had later been rehired with back pay.

General Superintendent Arnold Randall said Friday that media reports and "other concerns" prompted officials to re-examine O'Sullivan's work history, which included more than 20 years in operations and maintenance at the county hospital system.

“We went back and looked at John’s resume and found some discrepancies,” Randall said. “We discussed those issues and he offered his resignation and we accepted.”